Liouville theory: Ward identities for generating functional and modular geometry

摘要

We continue the study of quantum Liouville theory through Polyakov's functional integral \cite{Pol1,Pol2}, started in \cite{T1}. We derive the perturbation expansion for Schwinger's generating functional for connected multi-point correlation functions involving stress-energy tensor, give the "dynamical" proof of the Virasoro symmetry of the theory and compute the value of the central charge, confirming previous calculation in \cite{T1}. We show that conformal Ward identities for these correlation functions contain such basic facts from Kähler geometry of moduli spaces of Riemann surfaces, as relation between accessory parameters for the Fuchsian uniformization, Liouville action and Eichler integrals, Kähler potential for the Weil-Petersson metric, and local index theorem. These results affirm the fundamental role, that universal Ward identities for the generating functional play in Friedan-Shenker modular geometry \cite{FS}.